Sorry to hear about the crashes and thank you for the reports. This looks like an incompatibility with your current version of WebSense Endpoint. From time to time, a Websense update or a Firefox update results in a severe incompatibility. If this version of Websense is an unchangeable feature of your environment -- you can't update or disable it -- or if updating doesn't help, then you may want to try the following: Create a fake <code>qipcap.dll</code> file that will block Firefox from using the incompatible qipcap.dll file. Please see this post for more information on this option, which I have not tried myself: https://support.mozilla.org/questions/1111324#answer-847872